As an experienced Noob I can answer some of your questions.

#1

Definitely more lighting, I would look somewhere around 36-55 watts for your a setup. See ahsupply.com for their 36W and 55W retrofit kits. Or you could look at buying a fixture such as this for your 29g

Coralife Freshwater Aqualight Deluxe-Single 30" Strip at Big Al's Online

#2

No need for the airstone. It is useful in some tanks where additional aeration is needed because of low O2 at night.

#3

With decent lighting and excel these plants will grow well but not fast. Without CO2 injection some carpeting plants will take a very long time to fill out.

Will have to defer on the crayfish.

Your pictures look good. You may want to purchase some faster growing stem plants, that will help compete against algae and hide some of your equipment.

Good luck